The present invention relates to an improved method and apparatus for discharging particulate solids maintained in contact with fluid within a high pressure vessel.
The improvements provided in accordance with the present invention are broadly applicable to the discharge of particulate solids maintained in contact with fluids, i.e., liquid and/or gases, from vessels in which various types of reactions, conversions or the like operations are carried out at super-atmospheric pressure. However, the present invention is particularly useful in the withdrawal of particulate solids as for example catalyst material from a liquid hydrocarbon treatment zone. For example, the present invention has particular application in the removal of spent catalyst material from a treatment zone in which a heavy hydrocarbon oil is contacted with gaseous hydrogen at high temperatures as for example between about 200.degree. and 850.degree. C. and high pressures as for example between about 1000 and 5000 psig for the purpose of effecting hydrocracking, hydrodesulfurization or the like hydrogenation reactions. To effect hydrogenation reactions of this type, it has been found advantageous to pass the hydrocarbon material and hydrogen upwardly through a bed of particulate catalyst material under conditions such that the catalyst particles are maintained in random motion to become a so-called "ebullated" bed.
It is an object of the present invention to provide an efficient, expeditious and effective method and apparatus for discharging particulate solid in admixture with fluid from a high pressure vessel.
It is a further object of the present invention to provide a method and apparatus as aforesaid whereby the fluid may be efficiently and economically separated from the particulate solid.
It is a still further object of the present invention to provide an improved process and apparatus as aforesaid for removing particulate solid in admixture with liquid hydrocarbon and hydrogen from a high pressure hydrogenation zone.
The foregoing and further objects and advantages of the present invention will appear from a consideration of the following specification.